1. Field of the Invention
The present invention relates to a disc player, and more particularly to techniques for simplifying a mechanical construction for driving a pickup feeding mechanism which moves an optical pickup for reading information from an optical disc in a radial direction of the disc, and for simplifying a mechanical construction for detecting a mechanism status.
2. Description of the Related Art
The disc player for reading information from a disc (optical disc), such as a CD player, basically includes a disc rotating mechanism for rotating a disc on a turntable, a disc introducing mechanism for introducing the disc onto the turntable of a disc drive portion, and a pickup feeding mechanism for moving an optical pickup for reading information from the disc in a radial direction of the disc.
Three motors are respectively provided for those three mechanisms, and independently drive the latter. Quick response and high speed are essential to the performance of the disc rotating mechanism. To satisfy the requirements, the disc rotating mechanism is driven by a disc rotating mechanism motor directly coupled to the turntable.
The disc introducing mechanism sequentially moves the disc in vertical and horizontal directions with respect to a plane of the turntable. Therefore, the mechanism generally includes two types of operating members, a transport roller for transporting the disc onto the turntable along a horizontal plane, and a damper member for chucking the disc onto the turntable, and a shift plate for selectively controlling the two operating members. A disc introducing mechanism motor rectilinearly moves a shift plate to selectively control the transport roller or the damper member and to drive the transport roller to turn.
High precision is essential to the pickup feeding mechanism. Therefore, the optical pickup is rectilinearly moved with high precision by a lead screw engaging with the optical pickup, and the lead screw is driven to rotate by a pickup feeding mechanism motor located near the lead screw.
To select the driving of those mechanisms and an operation mode of a control circuit/signal processing circuit smoothly and at proper timings, the disc player includes plural kinds of detecting elements, such as detector sensor and detector switch. Specific examples of those detecting elements are a disc detecting element for detecting the insertion of a disc, a chucking end detecting element for detecting a chucking operation end in the disc introducing mechanism, and a pickup position detecting element for detecting that the optical pickup is at a disc inner-rim side position. Those detecting elements are used for the starting/stopping commands for drive selection of those mechanisms in the following ways.
A signal derived from a disc detecting element is used for a start command of starting up a disc introducing mechanism motor at the time of disc loading, and a stop command for stopping the disc introducing mechanism motor at the time of disc ejection, and others. A signal derived from the chucking end detecting element is used for a start command for the pickup feeding mechanism motor when a disc loading mode is shifted to a disc reproduction mode, a stop command for the disc introducing mechanism motor, and others. A signal derived from the pickup position detecting element is used for a start signal for the disc rotating mechanism motor in a disc reproduction mode, a stop signal for the disc rotating mechanism motor when the disc reproduction mode is shifted to the disc ejecting mode, a start signal for the disc introducing mechanism motor, and others.
The xe2x80x9cdisc inner-rim side positionxe2x80x9d of the optical pickup, which is to be detected by the pickup position detecting element is a position at which the optical pickup may read TOC (table of contents) information as management information stored in the disc inner-rim side area (lead-in area) of a disc recording area. In the disc reproduction mode, the optical pickup first reads the TOC information recorded in the lead-in area of the disc at this disc inner-rim side position, and a disc reproducing operation starts on the basis of the TOC information. The pickup position detecting element is provided for detecting that the optical pickup is at such a disc inner-rim side position.
The conventional disc player described above suffers from problems of requiring a large number of motors and detecting elements, and construction complexity.
In the conventional construction in which drive motors are respectively provided for the disc rotating mechanism, disc introducing mechanism and pickup feeding mechanism, three motors are required. In the mechanism, use of the three motors increases the number of component parts inclusive of motor support members and drive force transmission members, makes the related structure complicated, requires large parts occupying spaces, restricts the layout and design of related members, and brings about increase of the overall mechanism size and complexity of construction. The number of wires is also increased since electric power is supplied to the motors and those motors are controlled independently. Cost of the motors is relatively large in the cost of the overall mechanism. Thus, the use of three motors hinders the effort of reducing cost to manufacture.
In the conventional disc player, the three mechanisms are driven by their own motors, respectively. Accordingly, at least three detecting elements, a disc detecting element, a chucking end detecting element, and a pickup position detecting element, are required for the drive selection of the mechanism. Where the three kinds of detecting elements are used, the number of the wires for the detecting elements is increased. While the detecting element occupies a less space, the increase of the elements restricts the layout and design of related members, and makes the overall mechanism complicated.
An object of the invention is to solve the technical problems as mentioned above and to provide a disc player which reduces the number of the motors and the detecting elements and the number of related members inclusive of wires, and has advantages of improvement of parts layouts and design freedom, size reduction and simplification of the overall mechanism, cost reduction, and the like.
To solve the above problems, according to the present invention, a disc introducing mechanism or a pickup feeding mechanism are selectively driven by a single drive source, thereby succeeding in reducing the number of required drive sources.
Specifically, a disc player according to the invention basically includes a disc rotating mechanism for rotating a disc on a turntable, a disc introducing mechanism for introducing the disc onto the turntable of a disc drive portion, and a pickup feeding mechanism for moving an optical pickup for reading information on an optical disc in a radial direction of the disc.
In a disc player according to a first aspect of the invention, a disc positioning mechanism for positioning for positioning the disc on the turntable in accordance with a diameter of the disc is provided on the base member. The base member is supported on a chassis by an elastic member, and a floating lock mechanism is provided for fixing the base member at a fixed position on the chassis.
Thus, the disc positioning mechanism, together with the disc rotating mechanism, the disc introducing mechanism and the pickup feeding mechanism, are provided on the base member to be put in a floating state. Accordingly, it is little displaced when it is locked with the floating lock mechanism.
According to a second aspect of the present invention, the disc positioning mechanism includes a disc stopper for positioning the disc on the turntable, the disc stopper being urged by a disc introduced by the disc introducing mechanism to be movable, a lock portion being movable between a lock position for locking the disc stopper at a position based on a diameter of the disc and a lock removal position allowing the disc stopper to move, and a sensor portion for detecting a diameter of the disc by its contact with the disc, thereby controlling the lock portion.
In the disc player thus constructed, when a diameter of a disc introduced by the disc introducing mechanism requires a movement of the disc stopper, the sensor portion moves the lock portion to the lock removal position. In turn, the disc stopper is moved to a position corresponding to the disc diameter by the urging force of the introduced disc. When the sensor portion returns the lock portion to the lock position, the disc stopper stops to position the disc on the turntable. When the diameter of the disc introduced by the disc introducing mechanism does not require the movement of the disc stopper, the sensor portion locks the lock portion at the lock position. Accordingly, the introduced disc is stopped by the disc stopper to be positioned on the turntable. Thus, the disc player automatically recognizes a disc diameter and positions the disc on the turntable, without any special drive source.
According to a third aspect of the present invention, the disc player further comprises a select mechanism for selectively transmitting a drive force from a single drive source to the disc introducing mechanism or the pickup feeding mechanism.
Thus, the disc player is capable of driving both the disc introducing mechanism and the pickup feeding mechanism by the utilization of a drive force of a single drive source, by use of the select mechanism.
According to a fourth aspect of the invention, the select mechanism, the disc introducing mechanism and the pickup feeding mechanism are arranged as follows. The select mechanism includes a select member movable between a disc introducing position for transmitting a drive force to the disc introducing mechanism and a pickup feeding position for transmitting a drive force to the pickup feeding mechanism. The disc introducing mechanism includes disc introducing locking means for locking the select member at the disc introducing position in a disc introducing operation. The pickup feeding mechanism includes pickup feed locking means for locking the select member at the pickup feeding position in a pickup feeding operation.
In the disc player thus constructed, in the disc loading/ejecting operation, the select member is locked at the disc introducing position by the disc introducing locking means, where the coupling of the disc introducing mechanism with the drive side is reliably maintained. In the disc reproduction operation and when the optical pickup is returned to the original position, the select member is locked at the pickup feeding position by the pickup feeding locking means, whereby the coupling of the pickup feeding mechanism with the drive side is reliably maintained.
According to a fifth aspect of the invention, the disc introducing locking means is provided at a part of an operating member forming the disc introducing mechanism, and removes the locking of the select member when the operating member reaches an operation end position.
In the thus constructed disc player, in the disc loading/ejecting operation, the select member is locked at the disc introducing position by the operating member forming the disc introducing mechanism, whereby the coupling of the disc introducing mechanism with the drive side is reliably maintained. At the end of the operation of the operating member, its locking state is remove to allow the disc introducing mechanism from being separated from the drive side, and allow the select member to move to the pickup feeding position.
According to a sixth aspect of the invention, the disc introducing locking means is provided at a part of a select control member for selectively controlling the chucking of the disc to the turntable, and removes the locking of the select member when the operating member reaches a chucking end position.
In the thus constructed disc player, in the disc loading/ejecting operation, the select member is locked at the disc introducing position by the select control member, whereby the disc introducing mechanism with the drive side is reliably maintained. At the end of the chucking, its locking state is removed by the select control member to separate the disc introducing mechanism from the drive side, and to allow the select member to move to the pickup feeding position.
According to a seventh aspect of the invention, the optical pickup is positioned at the disc innermost position located more innerly than a disc inner-rim position allowing the optical pickup to read information in an inner area of an information recording area of the disc when the disc introducing mechanism operates, and when the optical pickup is at the disc innermost position, the pickup feeding locking means is held on the locking removal side, and when the optical pickup is located at the disc inner-rim side position and outside the disc inner-rim side position as radially viewed, the pickup feeding locking means is released and locks the select member at a pickup feeding position by the pickup feeding locking means.
In the thus constructed disc player, in the disc reproduction operation and when the optical pickup is returned to the original position, the select member is locked at the pickup feeding position by the pickup feeding mechanism, whereby the coupling of the pickup feeding mechanism with the drive side is reliably maintained. When the optical pickup reaches a position more innerly than a disc inner-rim side position during its returning operation, its locking state is removed to allow the pickup feeding mechanism from the drive side and allow the select member to move to the disc introducing position.
According to an eighth aspect of the invention, a detecting element for detecting that the optical pickup is at a disc inner-rim side position where the optical pickup may read information in an inner area of the information recording area of the disc, and detects the end of chucking the disc on the turntable by the utilization of an operation of the optical pickup.
This disc player is capable of detecting a chucking operation end in the disc introducing mechanism and a position of the optical pickup by use of a single detecting element. Therefore, the number of detecting elements is reduced when comparing with the disc player using the detecting elements for the respective mechanisms.
According to a ninth aspect of the invention, the optical pickup is positioned at the disc innermost position more innerly than the disc inner-rim side position when the disc introducing mechanism operates, and the detecting element detects the disc chucking operation end during a period that after the operation of the disc introducing mechanism ends, the optical pickup moves outward from the disc innermost position and reaches a position outside the disc inner-rim side position as radially viewed, and detects that the optical pickup is at a disc inner-rim side position during a period that the optical pickup moves toward the disc inner-rim side and reaches the disc inner-rim side position.
In this disc player, when the disc loading operation is shifted to the disc reproduction operation, the optical pickup is moved to a position somewhat outside the disc inner-rim side position as radially viewed. Thereafter, the optical pickup is returned to the disc inner-rim side position, thereby effecting the detection of the disc inner-rim side position of the optical pickup. Therefore, the chucking end and the position of the optical pickup can both be detected by merely adding a reciprocal motion of small distance in the vicinity of the disc inner-rim side position when the optical pickup is moved outward.
According to a tenth aspect of the invention, the select mechanism, the disc introducing mechanism, the pickup feeding mechanism, and the pickup feeding mechanism are arranged as follows. The select mechanism includes a select member movable between a disc introducing position for transmitting a drive force to the disc introducing mechanism and a pickup feeding position for transmitting a drive force to the pickup feeding mechanism. The disc introducing mechanism includes disc introducing locking means for locking the select member at the disc introducing position in a disc introducing operation. The pickup feeding mechanism includes pickup feed locking means for locking the select member at the pickup feeding position in a pickup feeding operation. When the optical pickup is at the disc innermost position, the pickup feeding locking means is held on the locking removal side. When the optical pickup is located at the disc inner-rim side position and outside the disc inner-rim side position as radially viewed, the pickup feeding locking means is released and locks the select member at a pickup feeding position by the pickup feeding locking means.
In the thus constructed disc player, in the disc loading/ejecting operation, the select mechanism is locked at the disc introducing position by the disc introducing locking means, whereby the coupling of the drive side with the disc introducing mechanism is reliably maintained. In the disc reproduction operation and when the optical pickup is returned to the original position, the select mechanism is locked at the pickup feeding position by the pickup feeding locking means, whereby the coupling of the drive with the pickup feeding mechanism is reliably maintained. At the end of the disc reproduction operation, the pickup feeding mechanism is reliably separated from the drive side by the utilization of the operation of the optical pickup. After the disc loading operation ends and the optical pickup reaches a disc inner-rim side position, the coupling of the drive side with the pickup feeding mechanism is reliably maintained by the pickup feeding locking means. Therefore, even if the optical pickup is returned to the disc inner-rim side position after the chucking operation ends, there is no chance that the pickup feeding mechanism is, against user""s will, separated from the drive side. Accordingly, following the pickup position detection, the optical pickup is moved outward with certainty. Good disc reproduction operation starts well.
According to an eleventh aspect of the invention, the detecting element is a detector switch is pressed by the optical pickup when the optical pickup is within a range from the disc innermost position to the disc inner-rim side position, and is separated from the optical pickup when the optical pickup moves outside the disc inner-rim position as radially viewed.
In this disc player, a position of the operating optical pickup can mechanically and reliably be detected by the detector switch.
According to a twelfth aspect of the invention, the pickup feeding mechanism includes a lead screw engages one end of the optical pickup to rectilinearly moves the optical pickup, and the detecting element is disposed on the opposite side of the optical pickup.
In this device, the detecting element is disposed a place on the opposite side of the lead screw, in which a free space is relatively large in the peripheral portion of the optical pickup. Freedom of laying out the elements is high, and it little affects the layout and design of other members.
According to a thirteenth aspect of the invention, the select mechanism includes a drive gear, an idler plate, and an idler gear as specified in the following. The drive gear is constantly coupled to the single drive source, and being rotated by a drive force of the drive source. The idler plate is provided as the select member, and is turned between a disc introducing position and a pickup feeding position by a friction interacting between it and the drive gear in accordance with a rotational direction of the drive gear. The idler gear is attached to one end of the idler gear so as to be constantly coupled to the drive gear, and is arranged such that the idler gear revolves with respect to the drive gear with the turn of the idler gear, when the idler gear is at the disc introducing position, the idler gear is coupled to the disc introducing mechanism, and when the idler plate is at the pickup feeding position, the idler gear is coupled to the pickup feeding mechanism.
The position of the idler plate is changed by a simple construction including the drive gear, idler plate and idler gear, and either of the disc introducing mechanism or the pickup feeding mechanism is reliably coupled to the drive source depending on the changed position.
According to a fourteenth aspect of the invention, the idler gear includes a disc introducing idler gear to be coupled to the disc introducing mechanism when the idler plate is at the disc introducing position, and a pickup feeding idler gear, provided separately from the disc introducing idler gear, to be coupled to the pickup feeding gear when the idler plate is at the pickup feeding position.
In this disc player, the idler gears may be located at appropriate positions to the disc introducing mechanism and the pickup feeding mechanism, thereby increasing design freedom.
According to a fifteenth aspect of the invention, the disc introducing mechanism and the idler gear are constructed as follows. The disc introducing mechanism includes a select control mechanism include a select control mechanism and a transport roller drive mechanism as constructed in the following. The select control mechanism selectively controls a damper member for chucking the disc on said turntable between the chucking side and the releasing side, and selectively controlling a transport roller for transporting the disc onto the turntable along a horizontal plane between a disc contact side and a disc releasing side. The transport roller drive mechanism drives the transport roller to turn. The idler gear includes a select control idler gear, transport roller drive idler gear, and a pickup feeding idler gear. The select control idler gear to be coupled to the select control mechanism when the idler plate is at the disc introducing position. The transport roller drive idler gear is provided separately from the select control idler gear, to be coupled to the transport roller drive mechanism when the idler plate is at the disc introducing position. The pickup feeding idler gear, provided separately from the select control idler gear and the transport roller drive idler gear, to be coupled to the pickup feeding idler gear when the idler plate is at the pickup feeding position.
In this disc player, the idler gears may be located at appropriate positions to the select control mechanism, the transport roller drive mechanism, and the pickup feeding mechanism, respectively. Therefore, design freedom is increased.